Do all Corniches plane a bit bows up?

[Nick2]

Now we seem to have sorted soot issue the next irritation is that my Fairline Corniche still assumes a rather bows up attitude when planing.

I know that these boats tend to do this but a flatter angle would be preferable.

Would bigger tabs help, or any other suggestions as I am running out of boat issues to worry about?

Thanks

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>

 

[longjohnsilver]

Get Joanne to drive and then you sit on the bows and it will plane just as you want /forums/images/icons/smile.gif

<hr width=100% size=1>

 

[BarryH]

Is all the weght in the stern. I find that I have to either move the beer or drink it. I would have thought the tabs fitted by the builders would have been sufficient. Whats in the stern. was it originally there or been added after it was built. Loads of things will affect the trim of the boat. When at rest does the boat float on an even keel. Is there any others you could compare it with. All questions I know but a good starting point.

<hr width=100% size=1>

 

[Talon2]

Missed the soot issue Nick. We have 31A's on our boat and suffer from smoke until they get really warmed up. Even then they leave a little black soot on back of boat. Was yours the same issue or am I in the wrong direction. Would be interested if you did sort it.

<hr width=100% size=1>Keith

<A target="_blank" HREF=http://www.mobiledit.co.uk>http://www.mobiledit.co.uk</A>

 

[Nick2]

There is a 37kg rib on davits, a mastervolt genny (90kg?) under the lazzerette and a few odds and ends such as spares kit but not too much.

The holding tank is in my greenhouse and the outboard in the conservatory and the boat does seem to sit as I would expect. The repitched props now cause the engines to rev as they should (3900 ish) and boat seems less stressed now.

We are running on full fuel tanks mounted either side of engines and no water.

Thats the picture now...

Thanks

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>

 

[Nick2]

Boy you sure did miss something here !!! The forum lived and almost breathed my soot issue for months (but I don't think I ever laboured the point) but as you are good enough to ask here goes..........

My Fairline Corniche has Volvo TAMD41s on shafts and even after a short run say to Cowes there would be 'orrid black soot over the transom, dinghy and even cockpit. The engines were also not revving to the suggested level and the performance was not up to scratch.

We replaced injectors, and had props repitched and also increased the ventilation to the engine bay by way of neat ducts and vents from the cockpit.

The soot has not as yet disappeared completely but it is so very much better and bearable. I have been advised that it may continue to improve as the engine clears itself out as we have done few hours so far since.

Hope this precis of a series of gripping and fascinating posts helps.

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>

 

[Renegade_Master]

you sure its not a semi dis/forums/images/icons/smile.gif............... wadda you mean the tanks in your greenhouse? oh I see it all goes straight out now saves full holding tanks good move.

<hr width=100% size=1><A target="_blank" HREF=http://www.suncoastmarine.co.uk>Sun Coast Sea School & Charter</A>

 

[omega2]

Hope I am not confounding the issue re the black smoke/soot, and your remedies so far, but have you checked out the airway joints from the turbos to the inlet manifold? if there are any leaks at all this will give you a dirty transom.

<hr width=100% size=1>J HAMER

 

[Nick2]

Thanks for the suggestion and I assume that engineer has done this but I will certainly check with him......

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>

 

[Deleted User YDKXO]

A friend of mine had a Corniche with 41's and it always looked as if it was planing bows up as well. Most boats plane at an angle of 5-8 degrees. Exactly how you measure this I dunno - maybe a graduated sprit level? There are so many Corniches about that if bows up trim was a problem, there would be a well known fix.
You could fit bigger tabs or even an additional set of fixed trim plates on the transom (quite a few manufacturers do this from new, particularly Sunseeker). Alternatively you could add weight at the bow - a good way to do this would be to lengthen the anchor chain and maybe fit a heavier anchor, worth doing anyway on most boats.
Whatever you do, just be aware that, generally speaking, most planing boats will lose speed the more you tab the boat down because there's more hull in the water to cause drag

<hr width=100% size=1>

 

[hlb]

All boats plane with bows up. Ok I can get mine flat. But thats just so I can see though window screen if downstairs. But it's dangerous in a following sea and uses more fuel/goes slower anyhow. Stick some Soltron in the 41's Sure you have been told before. Are you paying attention!!

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[apollo]

Yes, granted that absolutely Flat would cause extra drag and therefore waste power, not to mention the waves coming over the top. Been there done that.

But Nick's boat is VERY bow up.

Maybe in a blow that would be desirable, but for calm conditions he is wasting power.

The tabs he has doing nothing whatsover either to bring bow up or down.

(Nick - we should have checked when on the mooring whether the tabs go up and down when operated - you never know maybe the fuse has blown?)



<hr width=100% size=1>

 

[tico]

Hi
Good to meet you saturday
Just a couple of things
1. Check if the tabs actually work!!! Either fuse blown or lack of hydraulic oil !
2. BUT Olly hulls should run OK without any tab reqd, so i would look at excess weight at stern (RIB, outboard and genny).... how does it run when u take them off?

<hr width=100% size=1>Been there, done that, got the oily T shirt

 

[Wiggo]

1) Should be able to test the weight issue by seeing what happens if you get a couple of blokes to go and sit in the forecabin while running. Much easier than taking the genny out. If that levels the boat off, then it's a weight thing.

2) Our tabs did nothing at all last year. Eventually, we decided to test 'em properly, as we were stuck in Weymouth for a few days. A little investigation revealed that they work far better with hydraulic fluid in the reservoir... Worth a quick check.

<hr width=100% size=1><-- insert witty sig file here -->

<A target="_blank" HREF=http://www.fairlinetarga29.info>Buy my boat!</A>

 

[ari]

Corniches have excellent accomodation for their size. In order to get this they are very "full" in the bow, and as such have a lot of lift toward the front at speed. They all run bow up like this. Almost impossible to see out from down below when planing unless you stand up. Targa 33's of the same era (the old ones with the forward sloping arch) are exactly the same for the same reason.

Excellent boats both, but the bow up planing is unavoidable on these even with loads of tab down and drived trimmed in (on the Targa or sterndrive Corniche) and they tend to be very "thumpy" in a short head sea (as opposed to long swell where they just run up and down it).

<hr width=100% size=1>

 

[sonarbell]

Just looked at your pics. She looks a tad stern heavy. A mate of mine had the same engine setup on his corniche, when observed from a distance the antifouling waterline was level with the water, yours sits quite a way down at the stern. Only problems he had on his with soot was when he started them up and when he ran shit fuel. Fuel additive soon sorted it and decent fuel.

<hr width=100% size=1>

 

[Nick2]

You are correct as she certainly has been stern heavy and perhaps still is. Whilst we have removed the ally holding tank from the stern the genny is still there (90Kg or so) as is the rib (37kg but worse cos hanging over the stern). This evening I dug out a magazine photo of my actual boat whilst with a previous owner which was before my immediate predicessor added the genny and she still looked rather bows up. Might try without rib as would rather not lose genny but otherwise at a loss with what to do?

Thanks

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>